Bush-hammering machine



3 seets-sheet 1 4 C. FRST BUSH HAMMERING MACHINE Filed Jan.7, 1924 April 26;

April 2-, 1927.

C. FRST susa Humaine uAcHIN 3 Sheets-Shut 2 Flid Jan. '7. 1924 C. F RST BUSH HAMMERING MACHINE iled Jan. v. 1924 5 Sheets-Sheet 3.

Patented Apr. 26, 1927.

UNITED STATES cant. rasfr, 4or' BEDFORD, INDIANA.

BUSH-HAMMERING MACHINE.

Application led January 7, 1924. Serial No. 684,800.

My invention relates to the operation of surfacing or bush hammering building stone for the purpose of giving the same the rough finish sometimes desired. This 1 operation has usually been accomplished by use of a Sledge hammer wielded by hand and is a slow, expensive and laborious operati-on.

The object of my invention is to provide a machine whereby stone may be bush hammered automatically and much more expeditiously and at a lower cost than has been heretofore possible. Moreover, the work done by a machine constructed in accordance with my invention is more uniform in its character and generally more satisfactory than by the'method of hammering by hand.

The invention is illustrated, in a preferred embodiment, in the accompanying` drawings, wherein- Fig. 1 is a vertical sectional elevation of the apparatus. v

Fig. 2 is a fragmentary plan view of the stone after treatment to show the effect of the bush hammering operation.

Fig. 3 is a sectional view on line 3-3 of Fig. 2.

Fig. 4 is a fragmentary sectional plan of the machine.

Fig. 5 is a view, in elevation, with certain parts in section, of the motor and hammer.

Fig. 6 is a sectional view of the motor and hammer.

Fig. 7 is a detail view, in perspective, of the ratchet for imparting movements of partial rotation to the reciproca-ting element of the motor on the back strokes ofthe same.

Fig. 8 is a sectional view of the hammer.

Fig. 9 is a sectional plan, with thescale enlarged, on line 9-9 ofv Fig. 6, and l Fig; l() is an inverted plan view of the hammer and its guide frame.

Referring to the drawings, 1 designates an upright support formed with a guide web 2 on which is slidably arranged a transverse supporting member 3 adapted to en tend over a carriage l for supportingthe slab Aof stone 5 on which the machine open ates. The transverse supporting member 3 may be raised and lowered on the upright 1 by any suitable mechanism. I have shown a screwy 6 revoluble in a bearing 7 on the upright and*V havinga threaded engagement with; the member 3. The end of screw G may provided with a bevel gear 8 in mesh with a, bevel gear 9l on` a power shaft 10.

The transverse supporting member 3 is formed with a slideway 11 in which is a carrier 12 engaged by an adjusting screw 13 which turns in bearings 14e, 15 at the ends of the slideway and is provided with a hand wheel 16. A reciprocating moto'r 17, of any suitable type, preferably va motor operated by compressed air, is supported by brackets 18, 19 on a` plate 2O secured to a slide 21 vertically movable on a guide member 22 forming part of the carrier 12. An adjusting screw 23, revoluble in a bearing 24 on the carrier, has a threaded engagement with the slide 21 and is provided with a hand wheel 25 or other suitable means for revolving it. The reciprocating element or piston 26 of the motor is provided with a shank 27 to the tapered end k2d of which is fitted av bush hammering tool 9.9, the under surfacel of which is roughened preferably by cutting grooves therein at right angles to each other so that a series of pointed projections are provided for operating on the surface of the stone.

.It will be understood that the described structure for supporting the hammer and its operating motor above the stone so that the hammer and motor may be moved transversely with respect to the stone and also raised and lowered for slabs of different thickness, may be modied considerably without departure from my invention. Any

suitable means may be employed, other than the means shown, for effecting the vertical and horizontal adjustment of these parts. Similarly any suitable type of reciprocating motor may be employed for operating the hammer. l have shown in the drawings a common type of pneumatic motor, the air connections of which are designated 30, 31, lt will not be necessary to describe in detail the mecha 'am of the motor. For the species of'surfacing wor-lg the invention has particularly in view, that is, the production of surface on the stone such indicated in Fig. 2, it is necessary to rotate the hammer between impacts in order that the projections and indentations on the surface of the stone, after it has been bush hammered, should not have a straight line arrangement. rlhe particular efect desired would be spoiled if the stone had the appearance of being treated along straight lines. Consequently I employ for driving the hammer an expedient, common in pneumatic motors, for giving the reciprocating element of the motor a movement ot partial rotation at cach back stroke. ln the particular motor shown in the drawings, a spirally grou-ved shaft 33 extends through a correspondingly grooved nut in the upper end ot the piston 2G which is hollow. rlChe spiral shaft has a head 35 provided with pawls 36, 36 engaging the teeth oit a ratchet 37 in the upper end oi' the cylinder casing 38 or the motor. 0n the down stroke ot the piston the threaded shaft 33 will rotate. 0n the upstroke the engagement of the pawls 36 with the ratchet 37 prevents rotation ot the threaded shalt and as a consequence the piston 26 is rotated a part oit a turn and with it the hammer 2f). Any suitable i'neans, however, might be employed for rotating the hammer so that with successive impacts the angular positions ot the grooves or cuts on the 'tace ot the hammer are changed.

The carriage 4 which supports the stone is moved longitudinally, and preferably continuously, during the bush hanunering operation. l have shown the carriage as supported on longitudinal guideways 39 on a base 4G and provided on its under side with a worm rack 4l engaged by av worm 42 on a shaft 43 drive-n by a motor indicated at 44. Any suitable means (not shown) may be employed for automatically changing the direction ot the drive on the carriage at each end of its travel, or the motor may be controlled by hand to e'tlect the reversal ot the drive. f

The hammer Q9 is preferably guided .in its movements on vertically extending guide rods 45 forming part ot' a trame bolted to the casing 38 ot the motor. This trame comprises, in addition to the rods 45, a head 46 which is perforated for the bolts 47 with which the motor casing is provided, the head being secured to the top olf the motor casing by nuts 48 and being formed with perforations tor the upper ends of the guide rods 45 which latter are held in place in the head by screws 4 rllhe trame comprises additionally a cross piece consisting ot two members 50, 5l perforated 'for the guide rods and notched at opposite edges, as indicated at 52 to extend around the shank 2T of the motor piston, the members 50, 51 being secured together by screws 53. The hammer is termed with a circumferential groove 54 engaged by a guide yoke consistiifigr;` ot a pair ot members 55, 56 secured together by screws 57 and 'termed to provide oritices 58 'for the guide rods. ln the movements ot the hammer the yoke slides on the guide rods. In order to retract the hammer. from the stone, as soon as air is shut oli from the motor, thereby preventing the hammer from being ydragged by the stone, and bending shank 27 with possible injury to the other parts 0i the motor, l have provided a pair of coiled springs 59 engaging hooks 60 on the guide yoke 55, 56 and anchored to hooks 6l on the head 46.

The preferred operation of the apparatus above desci'ibed is as follows:

The slab of stone 5 is placed upon the carriage 4 and the proper vertical position ot the hammer above the stone is obtained by adjustment or' transverse support ll by screw 6, or of slide 2l by means of screw 23. Two vertical adjustments are provided as a matter of convenience. One would be suiiicient. The hammer and its motor are set to a position near the right hand edge ot' the stone (Fig. l) by manipulation ot the adjusting screw 13. The mechanism tor driving the carriage is then set in operation and the pneumatic motor started. rlhe usual p actice is to hammer a strip along one edge ot the stone while the carriage makes its movement in one direction and. to go over this same strip, without lateral adjustment ot the hammer, during the return movement ot the carriage. ly manipulation ot adjusting screw 13, and without stopping the movement of the carriage, the hammer is moved outwardly over thek stone a distance somewhat less than the diameter of the hammer. The motor is now set in operation and another strip of the stone is bush hammered, the hammer overlapping on the sur- 'face previously treated. For obtaining the effect illustrated in Fig. 2 the hammer is given a partial movement ot rotation, as previously described, between each impact. For this purpose the hammer turns readily in the guide yoke 55, 56. It a more regular effect is desired, that is, an arrangement ot the projections and indentations in the surface along straight lines, the mechanism for rotating the hammer may be eliminated and the guide yoke constructed so as to prevent any rotation ot the hammer.

As soon as the air is cut oil from the motor springs 59 react to pull the hammer out ot contact with the stone. rlhis is an important feature ot the machine as it would not do to have the hammer drag on the stone and it is not desirable or practical to stop the travel of the carriage whenever the pneumatic motor 'for driving the hammer is stopped. After the stone has been bush hammered over its entire surface as above described, it is inspected and if any part ot the surface is detective, shows lines, -tor example, this portion ot the stone can be brought under the hammer and re-suitaced.

I claim:

l. In a machine 'for bush hammering stone, the combination of a support for the stone, a hammer having a roughened under surface comprising` a plurality of stone-ene gaging projections, means for sustaining the hammer over the stone, a reciprocating motor for imparting vertical movements to the hammer in opposite 'directions comprising a floating element to which the hammer -is attached, means whereby the hammer' and stone support may be adjusted transversely relative to one another in one horizontal direction, and means for causing relative, continuous transverse movement in another horizontal direction between the hammer and the surface of the stone being operated on, means for giving movements of partial rotation to the hammer while out of contact with the stone, and springs arranged to retract the hammer from the stone as soon as the down stroke thereof is completed.

2. In a machine for bush hammering stone, the combination of a support for the stone, a. reciprocating motor sustained above said support, a hammer having a roughened under face attached to the lower end of the reciprocating element of the motor, a frame connected with the motor having vertical guide rods, a guide yoke engaging said hammer and slidable on said rods, and means whereby the stone support and motor may be given horizontal movements, one relative to the other,k in directions both longitudinal and transverse with respect to the surface of the stone being operated on.

3. In a machine for bush hammering stone, the combination of a support .for the stone, a reciprocating motor sustained above said support, a hammer having a roughened under face attached to the lower end of the reciprocating element of the motor, a frame connected with the motor having vertical guide rods, a guide yoke engaging said ham mer and slidable on said guide rods, springs connecting said yoke with said frame, and means whereby the stone support and motor may be given horizontal movements, one relative to the other, in directions both longitudinal and transverse with respect to the surface of the stone being operated on.

Il. In a machine for bush hammering stone, the combination of a support for the stone, a reciprocating motor sustained above said support, a hammer having a. roughened under face attached to the lower end of the reciprocating element of the motor, a frame connected with the motor having vertical guide rods, a guide yoke connected with said hammer by an engagement permitting the rotation of the hammer therein, means for imparting movements of partial rotation to the hammer while out of contact with the stone, and means whereby the stone support and motor may be given horizontal movements, one relative to the other, in directions bothlongitudinal and transverse with respect to the surface of the stone being operated on.

5. In a machine for bush hammering stone, the combination of a carriage for the stone, means for giving forward and back movements to the carriage, a guide member extending horizontally over the carriage, a carrier on said guide member, means for adjusting the position of the carrier lengthwise of the guide member, a reciprocating motor arranged verticallyv on said carrier, a hammer, the under surface of which is roughened, fixed to the lower end of the re` ciprocating element of the motor and adapted to impact with the stone on the carriage, a. frame attached to the motor comprising vertical guide rods, and a yoke connected with the hammer and slidable on said guide rods.

6. In a machine for bush hammering stone, the combination of a carriage for the stone, means for giving forward and back movements to the carriage, a guide member extending horizontally over the carriage, a carrier on said guide member, means for adjusting the position of the carrier lengthwise of the guide member, a reciprocating motor arranged vertically on said carrier, a hammer, the under surface of which is roughened, fixed to the lower end of the reciprocating element of the motor and adapted to impact with the stone on the carriage, a frame attached to the motor comprising vertical guide rods, a yoke connected with the hammer and slidable on said guide rods, and springs between said yoke and frame.

7. In a machine for bush hammering stone, the combination of a reciprocating motor, a frame connected with said motor comprising a pair of longitudinally extending guide rods, a hammer on the reciprocating element of the motor, a yoke connected with said hammer and slidable on said guide rods, and springs between said yoke and frame.

8. In a machine for bush hammering stone, the combination of a reciprocating motor, a frame connected with said motor comprising a pair of longitudinally extending guide rods, a hammer on the reciprocating element of the motor, a yoke connected with said hammer with an engagement permitting rotation therein of the hammer, springs between said yoke and frame, and means for imparting movements of partial rotation to the reciprocating element of the motor.

. CARL FURST. 

